Power-driven rock-drill.



M. KELLOW.

POWER DRIVEN ROCK. DRILL.

APPLICATION FILED 0:030. 1916.

Patented. Oct.15,-191&

2 SHEET$SHEET I --M. KELLOW.

POWER DRIVEN ROCK DRILL. APPLICATION FILED DEC- 30. i916.

Patented 0m; 15, 1918.

mama: unnunm'lm 2 $HEETS-SHEET 2.

POWER-DRIVEN ROCK-DRILL.

Specification of Letters Patent.

ares rarsngr orrren MOSES KELLOWyOF :PENBHYNDEUDRAETH, WALES.

Patented 0ct.1 5, 1918.

Original applicatinn filed July 11 1914, seria1 No. 850,455. Divided and this application filed December 30,

' V 191s; Serial No. 139,912.

To allwhom it mayconcern:

, Be itknown that I, Mosns KnLLow, a sub ject ofthe King of Great Britain and Ireland, residing at Penrhyndeudraeth, in the county of Merioneth, Wales, have invented new and useful Improvements in Power- Driven Rock-Drills, of which the following is a specification. Q p This invention relates to rock-drills of the type wherein a turbine or other suitable motor 1s employed for rotating the drill as,

described inthe specifications to Letters Patent of the United States granted to me and bearing date the 26th May 1908, No. 888,506,,and the "9th June 1908, No. 890,065, as also in the specification of my copending application Serial No. 850,455, filed July 11, 1914, of which the present application is a division. The present invention consists in certain improvements in power-drills of this class; particularly in regard to the construction and arrangement of the means for advancing and withdrawing the drill, and for controlling the supply of water under high pressure thereto.

for example, 1s

In the accompanying drawings, Figure 1' is a longitudinal section of a rock-drill embodying my present improvements; Fig. 2 being a transverse vertical section taken on the line Y in Fig. 1, and Fig. 3 an endview taken from the left-hand side of Fig. 1.

According to my present invention, the iston a employed for advancing and withdrawing the drill-rod b is so formed that it may be unscrewed from the end of the drillrod and removed as a complete unit. A recess in the central part of the piston contains packing a which is forced into position by the conical end of the drill-rod b, and a water-tight joint is thus formed by merely screwing the piston upon the drillrod.

As regards the feed-cylinders c, d within which the piston a works, it was, according to my prior construction, necessary to use an inner tube of considerable thickness, which had to be turned down along nearly its whole length in order to form the step necessary to prevent the outer cylinder slipping over it. According to the present construction, drawn tubing of uniform diameter is employed for the inner cylinder (1, as also for the outer cylinder 0, without entailward extremity and is applied to the correspondlng extremity of the outer cylinder 0.

For controllingthe admission of water to the cylinders c d and piston 11, the'passages gt are, according to my present invention, arranged more symmetrically, and the plug of the controlling device is of such a character as to admit of its being conveniently milled to the required form; the passages 9 being formed upon the exterior of the plug 9. Two cheese-headed screws 72. h are provided in connection with passages in, k, on either side; and, upon either of these' being removed,apressure-gage can be attached for testing purposes. When applied to the one side, and providing the control-valve is closed so as to prevent the passage of water therethrough, the gage indicates the pressure in the mains; and when attached to the other side, with the control-valve open as shown in the drawing, it indicates the pressure in the feed-cylinder available for keeping the drill up to its work. I

An indicator Z is attached to the plug g, in order to show the pressures present in the feed-cylinders corresponding with different positions of the regulating handle a. In the present illustration, the control valve is arranged upon the vertical center line of the drill, and an axial hole g is formed in the plug to permit the passage of the usual thrust-rod.

The water passing through the controlvalve from left to right, in the position shown in Fig. 2, is utilized for advancing the piston a, as drilling proceeds, and also for washing the debris out of the hole; the water passing, for this purpose, by Way of the passage through the piston a, and thence to the hollow drill-rod b. The passage through the piston is furnished with a spring-sustained valve 79 which, under high pressure, opens inward and permits water to pass through the drill-rod, but which, under low pressure, closes and prevents the escape of Water until actually" required for drilling purposes. If the piston a be stationary, with no Water passing down the drill-rod b, the pressure available in the feed-cylinder d and the passage is, corresponds With the static head, irrespective of any variation in the extent to Which the control-valve is opened; but, with an advance of the piston a and an escape of Water down the-drill-rod I), this pressure varies With the different degrees to Which the control-valve is opened. A plate m in front of a pointer is graduated according to the pressures read off, the pressure-gage, and indicates, With suflicient accuracy and Without the use of a pressure gage, the pressures .in the feed cylinder so long as the pressure in the mains continues uniform. I claim I 1. Ina power driven rock drill a feed cylinder comprising a sleeve having an internal circular shoulder, a tube fitting into the sleeveand abutting. against the shoulder, a second tube Within the first tube and separated therefrom, and a perforated ring attached at the end of the first tube and abutting against the free end of the second tube to hold it in position.

2. In a power driven rock drill a feed cylinder comprising a sleeve having an internal circular shoulder; atube fitting into the sleeve and'abutting the shoulder, a second tube Within the first tube and spaced therefrom to define an annular passageway, a ring attached to the end of the first tube, said ring abutting against the'free end of the second tube and having" an inner sun'- fac'ein alinement with the inner surface of the second tube, and a passage Way through the ring substantially in alinementiwith the annular passage Way betweentthe tubes MOSES 'KELLOW.

Witnesses: I 1' I L. SHAW," HUGH Bun on;

Copies of 'th is'paterit may be obtained fo'r five cents each, byaddressing the i COmIfiiSSiOiIG I of ,latents,

, Washington,'D. G. 

